Synthesize cgroup events by iterating cgroup filesystem directories.
The cgroup event only saves the portion of cgroup path after the mount
point and the inode number.
Signed-off-by: Namhyung Kim <namhy...@kernel.org>
---
tools/perf/builtin-record.c | 5 ++
tools/perf/util/cgroup.c | 3 +-
tools/perf/util/cgroup.h | 1 +
tools/perf/util/event.c | 115 ++++++++++++++++++++++++++++++++++++
tools/perf/util/event.h | 4 ++
tools/perf/util/tool.h | 1 +
6 files changed, 127 insertions(+), 2 deletions(-)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 359bb8f33e57..a6e3c4413b39 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1318,6 +1318,11 @@ static int record__synthesize(struct record *rec, bool
tail)
if (err < 0)
pr_warning("Couldn't synthesize bpf events.\n");
+ err = perf_event__synthesize_cgroups(tool, process_synthesized_event,
+ machine);
+ if (err < 0)
+ pr_warning("Couldn't synthesize cgroup events.\n");
+
err = __machine__synthesize_threads(machine, tool, &opts->target,
rec->evlist->core.threads,
process_synthesized_event,
opts->sample_address,
1);
diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c
index 8e4c26ea5078..274f0f29c72d 100644
--- a/tools/perf/util/cgroup.c
+++ b/tools/perf/util/cgroup.c
@@ -14,8 +14,7 @@ int nr_cgroups;
static struct rb_root cgroup_tree = RB_ROOT;
-static int
-cgroupfs_find_mountpoint(char *buf, size_t maxlen)
+int cgroupfs_find_mountpoint(char *buf, size_t maxlen)
{
FILE *fp;
char mountpoint[PATH_MAX + 1], tokens[PATH_MAX + 1], type[PATH_MAX + 1];
diff --git a/tools/perf/util/cgroup.h b/tools/perf/util/cgroup.h
index 11a8b187ec09..755f9712eda4 100644
--- a/tools/perf/util/cgroup.h
+++ b/tools/perf/util/cgroup.h
@@ -17,6 +17,7 @@ struct cgroup {
extern int nr_cgroups; /* number of explicit cgroups defined */
+int cgroupfs_find_mountpoint(char *buf, size_t maxlen);
struct cgroup *cgroup__get(struct cgroup *cgroup);
void cgroup__put(struct cgroup *cgroup);
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index c19b00c1fc26..9e71b9561f72 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -29,6 +29,7 @@
#include "stat.h"
#include "session.h"
#include "bpf-event.h"
+#include "cgroup.h"
#define DEFAULT_PROC_MAP_PARSE_TIMEOUT 500
@@ -296,6 +297,120 @@ int perf_event__synthesize_namespaces(struct perf_tool
*tool,
return 0;
}
+static int perf_event__synthesize_cgroup(struct perf_tool *tool,
+ union perf_event *event,
+ char *path, size_t mount_len,
+ perf_event__handler_t process,
+ struct machine *machine)
+{
+ size_t event_size = sizeof(event->cgroup) - sizeof(event->cgroup.path);
+ size_t path_len = strlen(path) - mount_len + 1;
+ struct stat64 stbuf;
+
+ while (path_len % sizeof(u64))
+ path[mount_len + path_len++] = '\0';
+
+ memset(&event->cgroup, 0, event_size);
+
+ event->cgroup.header.type = PERF_RECORD_CGROUP;
+ event->cgroup.header.size = event_size + path_len +
machine->id_hdr_size;
+
+ if (stat64(path, &stbuf) < 0) {
+ pr_debug("stat failed: %s\n", path);
+ return -1;
+ }
+
+ event->cgroup.ino = stbuf.st_ino;
+ event->cgroup.path_len = path_len;
+ strncpy(event->cgroup.path, path + mount_len, path_len);
+ memset(event->cgroup.path + path_len, 0, machine->id_hdr_size);
+
+ if (perf_tool__process_synth_event(tool, event, machine, process) < 0) {
+ pr_debug("process synth event failed\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+static int perf_event__walk_cgroup_tree(struct perf_tool *tool,
+ union perf_event *event,
+ char *path, size_t mount_len,
+ perf_event__handler_t process,
+ struct machine *machine)
+{
+ size_t pos = strlen(path);
+ DIR *d;
+ struct dirent *dent;
+ int ret = 0;
+
+ if (perf_event__synthesize_cgroup(tool, event, path, mount_len,
+ process, machine) < 0)
+ return -1;
+
+ d = opendir(path);
+ if (d == NULL) {
+ pr_debug("failed to open directory: %s\n", path);
+ return -1;
+ }
+
+ while ((dent = readdir(d)) != NULL) {
+ if (dent->d_type != DT_DIR)
+ continue;
+ if (!strcmp(dent->d_name, ".") ||
+ !strcmp(dent->d_name, ".."))
+ continue;
+
+ if (path[pos - 1] != '/')
+ strcat(path, "/");
+ strcat(path, dent->d_name);
+
+ ret = perf_event__walk_cgroup_tree(tool, event, path,
+ mount_len, process, machine);
+ if (ret < 0)
+ break;
+
+ path[pos] = '\0';
+ }
+
+ closedir(d);
+ return ret;
+}
+
+int perf_event__synthesize_cgroups(struct perf_tool *tool,
+ perf_event__handler_t process,
+ struct machine *machine)
+{
+ union perf_event event;
+ char *cgrp_root;
+ size_t mount_len; /* length of mount point in the path */
+ int ret = -1;
+
+ cgrp_root = malloc(PATH_MAX);
+ if (cgrp_root == NULL)
+ return -1;
+
+ if (cgroupfs_find_mountpoint(cgrp_root, PATH_MAX) < 0) {
+ pr_debug("cannot find cgroup mount point\n");
+ goto out;
+ }
+
+ mount_len = strlen(cgrp_root);
+ /* make sure the path starts with a slash (after mount point) */
+ strcat(cgrp_root, "/");
+
+ if (perf_event__walk_cgroup_tree(tool, &event, cgrp_root, mount_len,
+ process, machine) < 0)
+ goto out;
+
+ ret = 0;
+
+out:
+ free(cgrp_root);
+
+ return ret;
+}
+
static int perf_event__synthesize_fork(struct perf_tool *tool,
union perf_event *event,
pid_t pid, pid_t tgid, pid_t ppid,
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 0170435fd1e8..b4c4da69a771 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -735,6 +735,10 @@ int perf_event__synthesize_namespaces(struct perf_tool
*tool,
perf_event__handler_t process,
struct machine *machine);
+int perf_event__synthesize_cgroups(struct perf_tool *tool,
+ perf_event__handler_t process,
+ struct machine *machine);
+
int perf_event__synthesize_mmap_events(struct perf_tool *tool,
union perf_event *event,
pid_t pid, pid_t tgid,
diff --git a/tools/perf/util/tool.h b/tools/perf/util/tool.h
index 472ef5eb4068..3fb67bd31e4a 100644
--- a/tools/perf/util/tool.h
+++ b/tools/perf/util/tool.h
@@ -79,6 +79,7 @@ struct perf_tool {
bool ordered_events;
bool ordering_requires_timestamps;
bool namespace_events;
+ bool cgroup_events;
bool no_warn;
enum show_feature_header show_feat_hdr;
};
--
2.23.0.187.g17f5b7556c-goog
